When a person is unavailable, often because they are too busy,
injured, or taken. Can also refer to
objects that are broken and
not yet fixed.
Harry
won't be able to make my party; he says he's out of commission for
the next couple of months due to work.
Dang it, I caught an STI. I guess I'm out of commission until I finish my course of
antibiotics.
Ned's car is out of commission until he saves up enough money to fix it.